1. **State the problem:** We need to estimate the number of rings containing between 1.4 g and 3 g of gold using the histogram data. 2. **Recall the formula for frequency from a histogram:** $$\text{Frequency} = \text{Frequency density} \times \text{Class width}$$ 3. **Identify the relevant intervals and frequency densities:** - From 1 to 2 g, frequency density is about 50. - From 2 to 3 g, frequency density is about 40. 4. **Calculate the frequency for the part of the 1 to 2 g interval from 1.4 to 2 g:** - Class width = $2 - 1.4 = 0.6$ - Frequency = $50 \times 0.6 = 30$ 5. **Calculate the frequency for the 2 to 3 g interval:** - Class width = $3 - 2 = 1$ - Frequency = $40 \times 1 = 40$ 6. **Add the frequencies to estimate total rings between 1.4 g and 3 g:** $$30 + 40 = 70$$ 7. **Explain why this is an estimate:** The histogram groups data into intervals and assumes uniform distribution within each interval. Since the exact distribution of masses between 1.4 g and 2 g is unknown, the calculation is an approximation. **Final answer:** Approximately 70 rings contain between 1.4 g and 3 g of gold.